The Dangers of Playing Cat and Mouse with Adblock

There is a misconception about adblocking that prevents most people from understanding just how powerful it is. People naturally assume that adblock works by stopping ad content as it reaches the browser. In fact, it actually works by preventing requests for ad content from ever leaving the browser. Adblock patrols a border around every website, a border built not to stop things getting in, but designed to stop requests from getting out.

Draconian as it sounds, this is highly efficient for your internet connection. Waiting until ad data arrives before blocking it would consume megabytes of bandwidth, slowing things down and perhaps using up your data tariff.

The other implication is that publishers don’t get paid for pages viewed by adblock users. People who use adblock to send a message against invasive ads are not actually being heard by advertisers. They only succeed in getting a mixed message through to the website publisher, taking the content while denying them a payday and slowly contributing to probable closure during the next year or two.

Adblocking Iron Curtain

For most websites, adblock patrols an open border. Requests leave the browser, and although adblock checks the destination of each, it only turns away those destined for specific no-go ad servers.

It is less well known that adblock has an alternative strategy to the open border, reserved for websites that have attempted to circumvent it by playing “cat and mouse”. Typically, “cat and mouse” means the website publisher, or ad company working on its behalf, has tried to avoid being blocked by constantly changing the domain name of the ad server. Every time the domain name changes, the ads slip through for a little while. The adblock community quickly responds to reports of these unsolicited ads, and updates the rules on their blocklist. The ad server domain is then changed again, and adblock responds again. Some publishers (and ad tech companies) incorrectly assume that this game of cat and mouse can be played perpetually, maintaining a kind of stalemate with adblock.

They are wrong. With more cat-and mouse-games to play, adblock has begun to retaliate. The first example we heard of was from Germany, when a new kind of rule was added to the German-specific blocklist to deal with a particular ad network that was playing cat and mouse. The new rule placed a blanket ban on all requests to javascript files, while carving out a handful of exceptions to permit the core functionality of the website. It was as if adblock closed the border and an iron curtain dropped around the website. Instead of only turning away requests destined for no-go ad servers, it now blocked every web request not in possession of a special visa.

This closed-border approach is now the adblock community’s standard operating procedure when they encounter a game of cat and mouse being played. Over the last year we have even seen it happen to several US-based websites, each of which had permitted a third party to attempt to rescue their adblocked inventory with domain name rotation.

The Mouse Always Loses

Those websites are now worse off than when they began, permanently damaged in three serious ways:

The anti-adblock tech they were promised is permanently broken.

Their audience analytics systems (e.g., Google Analytics, Comscore or Sitecatalyst) are now broken. Their adblock visitors suddenly become invisible.

They have lost control of their own technology roadmap. They no longer have the ability to introduce new javascript-based functionality onto their websites without seeking permission from adblock first.

The key lesson here is to not get into cat-and-mouse games with domain name rotation. In this game, adblock is the cat, and it can catch the mouse any time it likes. Once provoked, they can retaliate and can decisively win in one simple move, leaving the website with far fewer options than it started out with.

The PageFair Way

At PageFair, we’ve been building a path through adblocking for years, and we learned this lesson a long time ago. We have never marketed cat-and-mouse tactics to publishers, although some of our direct competitors are doing so today. It goes against our values to do something so reckless with a client’s business, even if there was short-term gain to be had from it. Instead, we have spent these years developing a secure ad delivery technology that is fully invulnerable to adblocking, and therefore avoids the cat-and-mouse game entirely.

The problem with adblocking isn’t that adblock extensions exist; it’s that over 200 million people have chosen to install them on desktop browsers and over 400 million on mobile. Although our technology is invulnerable against browser adblock extensions, it only supports noninvasive ad formats that the vast majority of adblock users don’t find problematic. It can only be used to serve basic banner ads — the internet equivalent of magazine advertising. These static image ads are nonintrusive and light on bandwidth. We do not support any ad that auto-plays to distract the user’s attention. We do not support client-side scripting, which can put the end-users at risk from malvertising. Finally, we do not enable third-party cookie tracking.

This allows us to start over with an audience that has lost trust, and not succumb to pressure to start serving the kind of loud or malicious ads that so many millions of people are actively trying to escape. We are most successful when serving the innocent banner: the simplest ad format, which is safe, fast and perfectly sufficient for getting across the advertiser’s message.

We believe this is the breakthrough technology that will empower publishers to continue to build their businesses while focusing on their own brand and audience.